Abstract: As an x-ray tube expands and contracts during heating and cooling, its hermetic seal can be damaged. A more robust hermetic seal, particularly as the x-ray tube is heated and cooled, is desirable. The x-ray tube described herein can include a proximal-housing 13 and a distal-housing 14, which can be connected to each other by an interface-ring 15 for improved hermetic seal. Added x-ray tube weight, of material used for blocking x-rays, can make it difficult to transport the x-ray tube. Reducing this weight is desirable. A maximum outer diameter Dp of the proximal-housing 13 can be greater than a maximum outer diameter Dd of the distal-housing 14, for improved blocking of x-rays. This diameter difference can allow improved x-ray shielding with less material.

Abstract: X-rays can be used for material identification. X-ray beam purity, target adhesion the x-ray window, and a robust hermetic seal of the x-ray window are useful. To achieve these objectives, a target 17 can be mounted by an adhesion-layer 16 on the x-ray window. The adhesion-layer 16 can include chromium. A sealing-layer 13 can seal the x-ray window to a flange 19. Material of the sealing-layer 13 can be different from material of the adhesion-layer 16. There can be a gap 21 between the flange 19 and the target 17. There can be a conductive-layer 18 on the x-ray window 14 in the gap 21. A thickness Ts of the adhesion-layer 16 between the sealing-layer 13 and the x-ray window 14 can be different than a thickness Tt of the adhesion-layer 16 between the target 17 and the x-ray window 14.

Abstract: A planar filament for an x-ray tube can have a different cross-sectional area at different locations. In regions of smaller cross-sectional area, there can be higher current density, and thus increased heating and higher temperature of the wire. In regions of larger cross-sectional area, there can be lower current density, and thus decreased heating of the wire. Regions of larger cross-sectional area can also be stronger, thus reducing early filament failures. Wider regions can have increased area for electron emission. By adjusting the cross-sectional area and width of the wire at different locations, electron emission can be largely confined to a center of the filament, and filament life can increase.

Abstract: An x-ray tube can include an x-ray window sealed to a mount. An inner-collimator can be adjacent to, but not sealed to, the x-ray window. The inner-collimator can be sandwiched between the x-ray window and an insulating-layer. The insulating-layer can span an inner-collimator-aperture of the inner-collimator, forming an isolated cavity at the inner-collimator-aperture. Walls of the cavity can include the x-ray window, the inner-collimator, and the insulating-layer. The x-ray tube can have a light weight, can block x-rays in undesirable directions, and can shape the x-ray beam.

Abstract: An x-ray tube 10 can have (a) an enclosure electrically-insulating a cathode 11 from an anode 12; (b) a coating-ring 18 on an inner-face of the enclosure, the coating-ring 18 encircling a longitudinal-axis 16 of the enclosure; and (c) an interruption-ring 19 located at the inner-face of the enclosure at a different location than the coating-ring 18. The interruption-ring 19 can encircle the longitudinal-axis 16 at a different location along the longitudinal-axis 16 with respect to the coating-ring 18. The interruption-ring 19 can encircle the longitudinal-axis 16 at a different radius from the longitudinal-axis 16 than the coating-ring 18. The coating-ring 18 and the interruption-ring 19 can reduce uneven electrical charge build-up on the inner-face of the enclosure, and can protect the triple-point.

Abstract: An x-ray tube 10 can have (a) an enclosure electrically-insulating a cathode 11 from an anode 12; (b) a coating-ring 18 on an inner-face of the enclosure, the coating-ring 18 encircling a longitudinal-axis 16 of the enclosure; and (c) an interruption-ring 19 located at the inner-face of the enclosure at a different location than the coating-ring 18. The interruption-ring 19 can encircle the longitudinal-axis 16 at a different location along the longitudinal-axis 16 with respect to the coating-ring 18. The interruption-ring 19 can encircle the longitudinal-axis 16 at a different radius from the longitudinal-axis 16 than the coating-ring 18. The coating-ring 18 and the interruption-ring 19 can reduce uneven electrical charge build-up on the inner-face of the enclosure, and can protect the triple-point.

Abstract: X-ray transparent insulation can be sandwiched between an x-ray window and a ground plate. The x-ray transparent insulation can include aluminum nitride, boron nitride, or polyetherimide. The x-ray transparent insulation can include a curved side. The x-ray transparent insulation can be transparent to x-rays and resistant to x-ray damage, and can have high thermal conductivity. An x-ray window can have high thermal conductivity, high electrical conductivity, high melting point, low cost, and matched coefficient of thermal conductivity with the anode. The x-ray window can be made of tungsten. For consistent x-ray spot size and location, a focusing plate and a filament can be attached to a cathode with an open channel of the focusing plate aligned with a longitudinal dimension of the filament. Tabs of the focusing plate bordering the open channel can be bent to align with a location of the filament.

Abstract: A target for an x-ray tube can emit x-rays in response to impinging electrons. Some electrons rebound without interacting atomically to form x-rays. Problems of these non-interacting electrons include reduced x-ray flux, charging electrically-insulative components of the x-ray tube, and misdirecting the electron beam. The target can include an array of holes, an array of posts, or both. The holes/posts can increase electron interaction with material of the target. Consequently, a higher percentage of impinging electrons can form x-rays. The holes/posts can also allow the target to effectively generate x-rays of different energies by providing a target with multiple thicknesses. X-rays can be generated in thicker regions of the target with the x-ray tube operated at a larger voltage. X-rays can be generated in thinner regions of the target with the x-ray tube operated at a smaller voltage.

Abstract: An x-ray tube 10 can have (a) an enclosure electrically-insulating a cathode 11 from an anode 12; (b) a coating-ring 18 on an inner-face of the enclosure, the coating-ring 18 encircling a longitudinal-axis 16 of the enclosure; and (c) an interruption-ring 19 located at the inner-face of the enclosure at a different location than the coating-ring 18. The interruption-ring 19 can encircle the longitudinal-axis 16 at a different location along the longitudinal-axis 16 with respect to the coating-ring 18. The interruption-ring 19 can encircle the longitudinal-axis 16 at a different radius from the longitudinal-axis 16 than the coating-ring 18. The coating-ring 18 and the interruption-ring 19 can reduce uneven electrical charge build-up on the inner-face of the enclosure, and can protect the triple-point.

Abstract: X-ray transparent insulation can be sandwiched between an x-ray window and a ground plate. The x-ray transparent insulation can include aluminum nitride, boron nitride, or polyetherimide. The x-ray transparent insulation can include a curved side. The x-ray transparent insulation can be transparent to x-rays and resistant to x-ray damage, and can have high thermal conductivity. An x-ray window can have high thermal conductivity, high electrical conductivity, high melting point, low cost, and matched coefficient of thermal conductivity with the anode. The x-ray window can be made of tungsten. For consistent x-ray spot size and location, a focusing plate and a filament can be attached to a cathode with an open channel of the focusing plate aligned with a longitudinal dimension of the filament. Tabs of the focusing plate bordering the open channel can be bent to align with a location of the filament.

Abstract: X-ray transparent insulation can be sandwiched between an x-ray window and a ground plate. The x-ray transparent insulation can include aluminum nitride, boron nitride, or polyetherimide. The x-ray transparent insulation can include a curved side. The x-ray transparent insulation can be transparent to x-rays and resistant to x-ray damage, and can have high thermal conductivity. An x-ray window can have high thermal conductivity, high electrical conductivity, high melting point, low cost, and matched coefficient of thermal conductivity with the anode. The x-ray window can be made of tungsten. For consistent x-ray spot size and location, a focusing plate and a filament can be attached to a cathode with an open channel of the focusing plate aligned with a longitudinal dimension of the filament. Tabs of the focusing plate bordering the open channel can be bent to align with a location of the filament.

Abstract: An x-ray source can include an x-ray tube, and a heat sink for removal of heat from the x-ray tube. The heat sink can be thermally coupled to the anode and can extend away from the anode along a heat sink longitudinal axis. The heat sink can have a base and a fin extending from the base. The base can have a greater thickness nearer the anode, and a reduced thickness along the heat sink longitudinal axis to a smaller thickness farther from the anode.

Abstract: X-ray transparent insulation can be sandwiched between an x-ray window and a ground plate. The x-ray transparent insulation can include aluminum nitride, boron nitride, or polyetherimide. The x-ray transparent insulation can include a curved side. The x-ray transparent insulation can be transparent to x-rays and resistant to x-ray damage, and can have high thermal conductivity. An x-ray window can have high thermal conductivity, high electrical conductivity, high melting point, low cost, and matched coefficient of thermal conductivity with the anode. The x-ray window can be made of tungsten. For consistent x-ray spot size and location, a focusing plate and a filament can be attached to a cathode with an open channel of the focusing plate aligned with a longitudinal dimension of the filament. Tabs of the focusing plate bordering the open channel can be bent to align with a location of the filament.

Abstract: An x-ray source can include an x-ray tube, and a heat sink for removal of heat from the x-ray tube. The heat sink can be thermally coupled to the anode and can extend away from the anode along a heat sink longitudinal axis. The heat sink can have a base and a fin extending from the base. The base can have a greater thickness nearer the anode, and a reduced thickness along the heat sink longitudinal axis to a smaller thickness farther from the anode.

Abstract: An x-ray tube anode can include an electron hole extending from an electron entry at an exterior of the anode into a core of the anode, and an x-ray hole extending from an x-ray exit at the exterior of the anode into the core of the anode. The x-ray hole can intersect the electron hole at the core of the anode. In one embodiment, the electron hole and the x-ray hole can form a seamless bore from the electron entry to the x-ray exit. In another embodiment, the anode can be a single, integral, monolithic material with a single bore extending therethrough. In another embodiment, the core of the anode can include a target material located at a concave wall of the core of the anode.

Abstract: An x-ray tube anode can include an electron hole extending from an electron entry at an exterior of the anode into a core of the anode, and an x-ray hole extending from an x-ray exit at the exterior of the anode into the core of the anode. The x-ray hole can intersect the electron hole at the core of the anode. In one embodiment, the electron hole and the x-ray hole can form a seamless bore from the electron entry to the x-ray exit. In another embodiment, the anode can be a single, integral, monolithic material with a single bore extending therethrough. In another embodiment, the core of the anode can include a target material located at a concave wall of the core of the anode.

Abstract: An x-ray tube can provide x-ray spot stability, even for a small x-ray tube. The x-ray tube can have small target displacement, where target displacement is a displacement of the target material, towards the electron-emitter, along a longitudinal-axis of the anode, from x-ray powered-off state to stable operation, based on elongation of the anode. The x-ray tube can include a heatsink with an array of fins extending away from a base in opposite directions. A first fan can be attached to one end of the array of fins, oriented to face the base, and configured to direct an airstream towards the base. A second fan can be attached to opposite ends, oriented to face away from the base, and configured to draw the airstream from the base. Plate(s) can be located on sides of the fins to direct air flow from the first fan to the second fan.

Abstract: A x-ray tube comprising an anode sealed to a flexible coupling. The flexible coupling can allow the anode to deflect or tilt in various directions to allow an electron beam to impinge upon various selected regions of an anode target. A method of utilizing different regions of an x-ray tube target by tilting or deflecting an x-ray tube anode to cause an electron beam to impinge on a selected region of the target.

Abstract: A transmission x-ray tube comprising an end window hermetically sealed to a flexible coupling. The flexible coupling can allow the window to shift or tilt in one direction or another direction to allow an electron beam to impinge upon one region of the window or another region of the window. A method of utilizing different regions of an x-ray tube target by tilting an x-ray tube window at an acute angle with respect to an electron beam axis to cause an electron beam to impinge on a selected region of the window and tilting the window in a different direction to allow the electron beam to impinge on a different selected region of the window.

Abstract: Cathode assembly for a long throw length x-ray tube. In one example embodiment, a cathode assembly for an x-ray tube includes an electron emitter, an acceleration region, and a drift region. The electron emitter includes a curved emitting surface configured to emit an electron beam having a y-dimension that is greater than an x-dimension at the electron emitter. The acceleration region is defined adjacent to the electron emitter. The acceleration region is configured such that when the electron beam propagates within the acceleration region, the electron beam accelerates in a z-direction substantially normal to a midpoint of the curved emitting surface. The drift region is defined between the acceleration region and an anode. The drift region is configured such that the combined lengths of the drift region and the acceleration region are sufficient for the y-dimension to be less than the x-dimension at the anode.